Canvas is pretty fast for a lot of things. Check out Twiddla for an example of what you can pull off. It's just a bit limited in what it lets you do cross browser.

It's sort of like the days of IE4 vs NN3, with two technologies doing the same thing with a small common set of things you can do in both. Only now it's Canvas vs. SVG. You can accomplish a lot of stuff, and both can do a lot more, but there's just not enough overlap right now to really build anything truly cool.

It's not as pixel-by-pixel as you might think; canvas has a fillText() method (that is presumably implemented in native code) to draw text.